1. Field of the Invention
This invention relates to orthopaedic cervical collars, particularly those used in the treatment, stabilization and therapy of cervical trauma.
2. Description of Related Art
Various types of cervical collars have been developed in treating conditions of the neck and cervical spine. Some of these collars are intended merely as support for whiplash and other such injuries where support for the head and neck is needed. The primary objective for the use of such a collar is to partially immobilize the head and neck, to maintain a desired spinal alignment, to provide support for the head, and to relieve any spasm or strain to which the neck muscles may be subjected by transmitting weight or force from the head to the shoulders or adjacent area.
Other collars are intended to be used where near complete immobilization of the head and neck are necessary such as in an EMS pre-hospital setting. There are a multitude of cervical collars intended to perform one or more of the above-mentioned functions.
U.S. Pat. No. 3,572,328 to John L. Bond describes an adjustable, flexible cervical collar designed for universal use by providing vertically adjustable movable sections displaceable relative to one another and to a base portion.
U.S. Pat. No. 2,911,970 to W. L. Bartles pertains to a cervical collar having two piece construction which allows for adjustment of the forward portion of the cervical collar. This allows for the use of a single collar by persons having different length necks as measured in the front of the person.
Other collars intended for partial or total immobilization are shown in U.S. Pat. No. 4,413,619 and Reissue No. 32,219 to Garth. Such collars are generally made by die-cutting plastic sheet material and attaching various pieces together to form a collar. Die cut collars have two specific problems.
The first problem with die cut collars relates to the flexibility of the material from which the collar is formed. The material selected must be flexible enough to conform to the neck and head of the patient, while being sufficiently rigid to maintain the head of the patient in a fixed, predetermined spatial relationship with the body of the patient.
The second problem with die cut collars, as with all die-cut materials, is that no matter how well the pieces may be designed, there is always waste involved between pieces die-cut from a sheet. There is also waste from holes cut in those pieces. Accordingly, it would be more economical if such a collar could be produced by injection molding.
Injection molding of cervical collars has been previously attempted. U.S. Pat. No. 5,038,759 to Morgenstern shows an injection molded cervical orthopaedic device. While this solves the second problem by minimizing the waste generated by die cutting collars, it does not address the first problem of physical characteristics of the material from which the collar is formed.
The material forming the collar must be sufficiently flexible to allow the collar to conform to the neck of the patient on which it is placed. Yet the collar must have sufficient rigidity to hold the patient's neck in a predetermined position and sufficient toughness to withstand continued use. Of course, in the case of injection molding, the material must also be injection moldable. Most injection moldable materials strong and tough enough to maintain the head of a patient in a predetermined position are too stiff to be useful as a material for a cervical collar. Even those materials which might be difficult to mold do not normally meet these conflicting criteria. Finally, the chosen material should cause a minimum of interference with x-rays, magnetic resonance imaging and other diagnostic procedures. Few or no materials can meet all of these demands in a conventional molded or die cut cervical collar.